They are said to have strayed from plans to incorporate "country of origin
controls, under which UK-based companies need only comply with UK laws for their activities to be legal in any of the other 14 EU member states.
Instead, the government proposals suggest local laws may be allowed to prevail when advertisers use the internet in Europe. Now, the Advertising Association is urging the Prime Minister's policy advisers to think again.
Andrew Brown, the AA's director-general, said: "The transposition of the 'country of origin' principle into UK law is of vital importance to the advertising industry of this country."
The AA has warned that unless the principle is enshrined in UK law, British companies will be put at a serious competitive disadvantage against rivals in other EU countries.